Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0734 DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT ATF CONDITION Inspect ATF condition. (See AUTOMATIC TRANSMISSION FLUID (ATF) INSPECTION .) Is it normal?	Yes	Go to the next step.
3		No	Replace ATF, then go to Step 10.
4	INSPECT ATF LEVEL Start the engine. Warm up AT. Is the ATF level within the specification? (See AUTOMATIC TRANSMISSION FLUID (ATF) INSPECTION .)	Yes	Go to the next step.
4		No	Add ATF to the specified level, then go to Step 10.
5	INSPECT SHIFT SOLENOID VALVE A AND F Inspect the shift solenoid valves A and F. (See SOLENOID VALVE INSPECTION .) Are the shift solenoid valves normal?	Yes	Go to the next step.
5		No	Replace the shift solenoid valve, then go to Step 10. (See SOLENOID VALVE REMOVAL/INSTALLATION .)
6	INSPECT LINE PRESSURE Start the engine. Measure each line pressure. Specification D, M range Idle: 320-450 kPa {3.3-4.6 kgf/cm ² , 46-65 psi} Stall: 1,130-1,330 kPa {11.5-13.6 kgf/cm ² , 164-193 psi} R position Idle: 380-580 kPa {3.9-5.9 kgf/cm ² , 55-84 psi} Stall: 1,470-1,700 kPa {15.0-17.3 kgf/cm ² , 213-247 psi} P, N position Idle: 380-580 kPa {3.9-5.9 kgf/cm ² , 55-84 psi} Are the line pressure measurements within the specifications? (See LINE PRESSURE TEST .)	Yes	Go to the next step.
6		No	Inspect or replace the applicable part according to the line pressure test results, then go to Step 10.
7	INSPECT STALL SPEED Measure the stall speed in D range. (See STALL SPEED TEST .) Specification 2,100-2,750 rpm Is the stall speed within the specification?	Yes	Go to the next step.
7		No	Inspect or replace the applicable part according to the stall test result, then go to Step 10.
8	INSPECT FREQUENCY OF TURBINE SENSOR WHEN DRIVING VEHICLE Turn the ignition switch to the LOCK position. Connect the WDS or equivalent. Start the engine. Measure the frequency of the turbine sensor while driving the vehicle under the following conditions: Vehicle speed (VSS PID): 20 km/h {12 mph} Drive in D range, 1GR Is the turbine sensor frequency approx. 1,100 Hz ?	Yes	Go to Step 10.
8		No	Go to the next step.
9	INSPECT EACH SHIFT VALVE AND RETURN SPRING CONDITION OF CONTROL VALVE Turn the ignition switch to the LOCK position. Remove the control valve body. Disassemble the control valve body. Inspect the following: Each valve condition Each return spring condition Oil passage clogging Is the control valve body normal?	Yes	Replace the automatic transmission, then go to the next step. (See AUTOMATIC TRANSMISSION REMOVAL/INSTALLATION .)
9		No	Repair or replace any malfunctioning shift valves and/or return springs, then go to the next step.
10	VERIFY TROUBLESHOOTING OF DTC P0734 COMPLETED Make sure to reconnect all disconnected connectors. Clear DTC using the WDS or equivalent. Start the engine. Warm up AT. Drive the vehicle under the following conditions at least 1 times for 1 s or more. ATF temperature: 20 °C {68 °F} or more Drive in D range, 4GR Throttle opening angle (TOHP PID): 12.5% or more Vehicle speed (VSS PID): 40 km/h {25 mph} or more Is the same DTC present?	Yes	Replace the TCM, then go to the next step. (See TCM REMOVAL/INSTALLATION .)
10		No	Go to the next step.
11	VERIFY AFTER REPAIR PROCEDURE Perform the "After Repair Procedure". (See AFTER REPAIR PROCEDURE .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
11		No	DTC troubleshooting completed.